noun
intestinal bacteria; gut bacteria
Refers to the microorganisms living in the intestines; used in medical, nutritional, and everyday contexts.
腸内細菌のバランスが健康に影響を与える。
The balance of gut bacteria affects health.
腸内フローラ (intestinal flora) is a near-synonym often used in scientific contexts, while 腸内細菌 is more direct and common.
Compound of 腸内 (intestine) + 細菌 (bacteria).